In preparing a tooth for the application of a crown or a bridge, it is necessary to remove portions of the tooth. Conventionally this is done by grinding or drilling. In removing this material, it is important to leave a stub of the tooth which is properly shaped to receive and support the crown or bridge, and at the same time it is essential not to invade the pulp cavity within the tooth. Further, for the convenience of both the doctor and patient it is important for the preparation to be performed as quickly as possible.
The present invention relates to an apparatus and method for drilling teeth, and particularly to an apparatus and method for simply and accurately determining an appropriate drill bit size and configuration for preparing a tooth for a crown or bridge.
The apparatus and method of the invention enables a dentist to determine quickly the appropriate drill bit for precise and efficient reduction of the tooth structure.
One aspect of the invention comprises the apparatus for drilling the tooth and determining the proper drill bit form for the particular tooth. The apparatus comprises a kit including special measuring guides (described more fully hereinafter) and a plurality of drill bits. The guides enable the dentist to determine the proper drill bit form, and the drill bits are proportioned to provide a system for properly drilling the teeth.
A specific aspect of the invention comprises a system for determining the proper drill bit to use for a given tooth. That structure comprises a pair of transparent sheets which are designed to provide visual information about a tooth and the drill bit most suited therefor. When superimposed on an X-ray of the tooth to be prepared, the transparent sheets can be used to determine the proper drill bit form for drilling the tooth.
Still further the invention comprises a method for selecting the proper drill bit for drilling or shaping a tooth. According to the method, an X-ray is provided of the tooth to be prepared, and a first measuring sheet is superimposed on the X-ray to provide a visual picture of the dimension of the tooth. A second transparent sheet or template carries the profiles of a selection of different drill bits. When the template is superimposed on the first sheet, it provides a visual impression of the amount of tooth material each bit would remove if used on the selected tooth. The proper bit is the one which will in a single pass remove the desired amount of tooth while leaving a safe margin surrounding the pulp cavity and without cutting into neighboring teeth.
These and other features of the present invention will become clear from the following specification when taken together with the accompanying drawings.